EFFICIENT FORMATION OF MOLECULAR-OXYGEN CLUSTER ANIONS IN AN EXCIMER LASER-ABLATED (308 NM) FULLERENE SOURCE

The reaction of molecular oxygen clusters with laser-ablated (308 nm) hot fullerenes was studied in a molecular beam/time-of-flight mass spectrometer. Molecular oxygen cluster anions (O-2)(n)(-) were efficiently produced with n ranging from 1 to 15. The cluster anion formation is mainly attributed to the electron transfer from hot fullerenes (perhaps the fullerene molecular Rydberg states) to the oxygen clusters. The reaction of oxygen with the fullerenes also resulted in the formation of small carbon cluster anions (n = 3-20) and C60O-, C58O-, C70O- and C68O-. Among the fullerene oxide anions formed, C58O- and C68O- were dominant. O-2(-) was shown to activate the fullerene disintegration to form small carbon cluster anions